Do not override Bearer 3gpp profile properties during connection
When connecting via AT commands requiring a 3gpp profile with undefined profile-id, the corresponding bearer 3gpp profile is later modified adding the selected PDP context.
For this reason when a next connection is requested with the same properties (that is no profile-id) the already existing bearers is not selected because of the different profile-id value and a new one is created.
This change lets the connection logic use a copy of the user-requested bearer's 3gpp profile which can be modified for the logic needs, but it is not stored and then does not compromise a bearer comparison in a next connection request.
Fixes #572 (closed)